- Environment & Hardware
OS: Fedora 44
Compositor: Wayland (Mutter)
Kernel: 7.1.3-200.fc44.x86_64
Hardware: ASUS ROG Flow Z13 (2025)Display: 13.4" eDP, 2560x1600 Native, 180Hz
GPU: AMD 8060S (integrated graphics).
Observed Behavior : When utilizing fractional display scaling (e.g., 125% or 133%), the system exhibits severe visual degradation, including gray desynchronization blocks and green/purple VRAM corruption squares. This occurs specifically during rapid virtual desktop switching or dynamic GNOME UI micro-updates. Additionally, the system generates disproportionate thermal load and GPU compute overhead during heavy graphical applications like home page of Steam (lots of graphical elements of steam sales etc…) - Mechanical Analysis & Reproduction: The visual degradation is the direct result of a compound systemic collision between user-space rendering instructions and kernel-level power management.
The Software Load: If i’m not wrong Mutter handles the 133% fractional scale by forcing a 200% virtual over-render (5120 x 3200), followed by a continuous hardware downscale back to 2560 x 1600. This maximizes the AMD Display Core (DC) processing load.
The Hardware Timing: The amdgpu driver attempts to enforce aggressive Panel Self Refresh (PSR) sleep/wake cycles.
The “Problem”: The AMD Display Core synchronization logic fundamentally fractures when attempting to process Mutter’s heavy fractional downscaling and independent hardware cursor/UI plane updates alongside the high-frequency PSR state toggling required by a 180Hz panel. The hardware fails to synchronize the sleep states with the compositor’s frame delivery, resulting in dropped data and visual artifacts. - Validated WorkaroundsIsolating PSR: Appending amdgpu.dcdebugmask=0x10 to the GRUB boot arguments mathematically bypasses the PSR logic entirely. This relieves the timing pressure on the display core and restores visual stability, confirming the driver’s sleep states as the direct catalyst for the desynchronization
Isolating Render Load: Setting a strict 100% integer scale at a lowered 1920 x 1200 physical resolution (bypassing the over-render/downscale pipeline) drastically reduces thermal output and GPU overhead, highlighting the mechanical inefficiency of the legacy fractional scaling method.
4.Request for Review : This report is submitted to highlight the architectural friction between compositor-level over-rendering and the amdgpu module’s power-saving routines on high-density, high-refresh panels. I request a review of the PSR interaction with Mutter’s current fractional scaling pipeline under kernel 7.1.x. (which was present since Kernel 6.5…).
For record, this use doesn’t persist when i use my Windows SSD of the machine so the problem is probably on the software level of interaction between my machine and FedoraOS/Wayland + mutter.